Field of the Invention
The present invention relates to an organic light emitting diode (OLED) display and a manufacturing method thereof. More particularly, the present invention relates to an OLED display using thin film encapsulation, and a manufacturing method thereof.
Description of the Related Art
Unlike a liquid crystal display, the OLED display has a self-emitting characteristic and does not need a separate light source such that the thickness and weight thereof are decreased. In addition, since the OLED display involves high quality characteristics such as low power consumption, high luminance, and short response time, it is spotlighted as a next generation display device for portable electronic appliances.
The OLED display includes a plurality of organic light emitting diodes, each having a hole injection electrode, an organic emission layer, and an electron injection electrode. Light is generate by energy generated when exciton generated by combining electrons and holes in an organic emission layer falls from an exited state to a ground state, and the OLED display displays the image using the same.
However, the organic emission layer sensitively reacts to the external environment such as moisture and oxygen. Thus, when the organic emission layer is exposed to moisture and oxygen, quality of the OLED display may deteriorate. Accordingly, in order to protect an organic light emitting diode and prevent permeation of moisture or oxygen into the organic emission layer, an encapsulation substrate may be attached in an air-tight manner to a display substrate where the organic light emitting diode is formed, or a thin film encapsulation may be formed on the organic light emitting diode.
In particular, the entire thickness of the OLED display can be significantly reduced by using the thin film encapsulation rather than using the encapsulation substrate. Furthermore, it is advantageous to realize a flexible display.
However, the OLED display using the thin film encapsulation can effectively prevent permeation of moisture or oxygen along a direction perpendicular to the substrate, but moisture or oxygen may be easily permeated into the substrate along an interface of the thin film encapsulation in a direction parallel to the substrate at an edge of the substrate.
The above information disclosed in this Background section is only for enhancement of an understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.